6 handy Bash scripts for Git | Opensource.com

6 handy Bash scripts for Git

These six Bash scripts will make your life easier when you're working with Git repositories.

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I wrote a bunch of Bash scripts that make my life easier when I'm working with Git repositories. Many of my colleagues say there's no need; that everything I need to do can be done with Git commands. While that may be true, I find the scripts infinitely more convenient than trying to figure out the appropriate Git command to do what I want.

1. gitlog

gitlog prints an abbreviated list of current patches against the master version. It prints them from oldest to newest and shows the author and description, with H for HEAD, ^ for HEAD^, 2 for HEAD~2, and so forth. For example:

$ gitlog
-----------------------[ recovery25 ]-----------------------
(snip)
11 340d27a33895 Bob Peterson     gfs2: drain the ail2 list after io errors
10 9b3c4e6efb10 Bob Peterson     gfs2: clean up iopen glock mess in gfs2_create_inode
 9 d2e8c22be39b Bob Peterson     gfs2: Do proper error checking for go_sync family of glops
 8 9563e31f8bfd Christoph Hellwig gfs2: use page_offset in gfs2_page_mkwrite
 7 ebac7a38036c Christoph Hellwig gfs2: don't use buffer_heads in gfs2_allocate_page_backing
 6 f703a3c27874 Andreas Gruenbacher gfs2: Improve mmap write vs. punch_hole consistency
 5 a3e86d2ef30e Andreas Gruenbacher gfs2: Multi-block allocations in gfs2_page_mkwrite
 4 da3c604755b0 Andreas Gruenbacher gfs2: Fix end-of-file handling in gfs2_page_mkwrite
 3 4525c2f5b46f Bob Peterson     Rafael Aquini's slab instrumentation
 2 a06a5b7dea02 Bob Peterson     GFS2: Add go_get_holdtime to gl_ops
 ^ 8ba93c796d5c Bob Peterson     gfs2: introduce new function remaining_hold_time and use it in dq
 H e8b5ff851bb9 Bob Peterson     gfs2: Allow rgrps to have a minimum hold time

If I want to see what patches are on a different branch, I can specify an alternate branch:

$ gitlog recovery24

2. gitlog.id

gitlog.id just prints the patch SHA1 IDs:

$ gitlog.id
-----------------------[ recovery25 ]-----------------------
56908eeb6940 2ca4a6b628a1 fc64ad5d99fe 02031a00a251 f6f38da7dd18 d8546e8f0023 fc3cc1f98f6b 12c3e0cb3523 76cce178b134 6fc1dce3ab9c 1b681ab074ca 26fed8de719b 802ff51a5670 49f67a512d8c f04f20193bbb 5f6afe809d23 2030521dc70e dada79b3be94 9b19a1e08161 78a035041d3e f03da011cae2 0d2b2e068fcd 2449976aa133 57dfb5e12ccd 53abedfdcf72 6fbdda3474b3 49544a547188 187032f7a63c 6f75dae23d93 95fc2a261b00 ebfb14ded191 f653ee9e414a 0e2911cb8111 73968b76e2e3 8a3e4cb5e92c a5f2da803b5b 7c9ef68388ed 71ca19d0cba8 340d27a33895 9b3c4e6efb10 d2e8c22be39b 9563e31f8bfd ebac7a38036c f703a3c27874 a3e86d2ef30e da3c604755b0 4525c2f5b46f a06a5b7dea02 8ba93c796d5c e8b5ff851bb9

Again, it assumes the current branch, but I can specify a different branch if I want.

3. gitlog.id2

gitlog.id2 is the same as gitlog.id but without the branch line at the top. This is handy for cherry-picking all patches from one branch to the current branch:

$ # create a new branch
$ git branch --track origin/master
$ # check out the new branch I just created
$ git checkout recovery26
$ # cherry-pick all patches from the old branch to the new one
$ for i in `gitlog.id2 recovery25` ; do git cherry-pick $i ;done

4. gitlog.grep

gitlog.grep greps for a string within that collection of patches. For example, if I find a bug and want to fix the patch that has a reference to function inode_go_sync, I simply do:

$ gitlog.grep inode_go_sync
-----------------------[ recovery25 - 50 patches ]-----------------------
(snip)
11 340d27a33895 Bob Peterson     gfs2: drain the ail2 list after io errors
10 9b3c4e6efb10 Bob Peterson     gfs2: clean up iopen glock mess in gfs2_create_inode
 9 d2e8c22be39b Bob Peterson     gfs2: Do proper error checking for go_sync family of glops
152:-static void inode_go_sync(struct gfs2_glock *gl)
153:+static int inode_go_sync(struct gfs2_glock *gl)
163:@@ -296,6 +302,7 @@ static void inode_go_sync(struct gfs2_glock *gl)
 8 9563e31f8bfd Christoph Hellwig gfs2: use page_offset in gfs2_page_mkwrite
 7 ebac7a38036c Christoph Hellwig gfs2: don't use buffer_heads in gfs2_allocate_page_backing
 6 f703a3c27874 Andreas Gruenbacher gfs2: Improve mmap write vs. punch_hole consistency
 5 a3e86d2ef30e Andreas Gruenbacher gfs2: Multi-block allocations in gfs2_page_mkwrite
 4 da3c604755b0 Andreas Gruenbacher gfs2: Fix end-of-file handling in gfs2_page_mkwrite
 3 4525c2f5b46f Bob Peterson     Rafael Aquini's slab instrumentation
 2 a06a5b7dea02 Bob Peterson     GFS2: Add go_get_holdtime to gl_ops
 ^ 8ba93c796d5c Bob Peterson     gfs2: introduce new function remaining_hold_time and use it in dq
 H e8b5ff851bb9 Bob Peterson     gfs2: Allow rgrps to have a minimum hold time

So, now I know that patch HEAD~9 is the one that needs fixing. I use git rebase -i HEAD~10 to edit patch 9, git commit -a --amend, then git rebase --continue to make the necessary adjustments.

5. gitbranchcmp3

gitbranchcmp3 lets me compare my current branch to another branch, so I can compare older versions of patches to my newer versions and quickly see what's changed and what hasn't. It generates a compare script (that uses the KDE tool Kompare, which works on GNOME3, as well) to compare the patches that aren't quite the same. If there are no differences other than line numbers, it prints [SAME]. If there are only comment differences, it prints [same] (in lower case). For example:

$ gitbranchcmp3 recovery24
Branch recovery24 has 47 patches
Branch recovery25 has 50 patches

(snip)
38 87eb6901607a 340d27a33895 [same] gfs2: drain the ail2 list after io errors
39 90fefb577a26 9b3c4e6efb10 [same] gfs2: clean up iopen glock mess in gfs2_create_inode
40 ba3ae06b8b0e d2e8c22be39b [same] gfs2: Do proper error checking for go_sync family of glops
41 2ab662294329 9563e31f8bfd [SAME] gfs2: use page_offset in gfs2_page_mkwrite
42 0adc6d817b7a ebac7a38036c [SAME] gfs2: don't use buffer_heads in gfs2_allocate_page_backing
43 55ef1f8d0be8 f703a3c27874 [SAME] gfs2: Improve mmap write vs. punch_hole consistency
44 de57c2f72570 a3e86d2ef30e [SAME] gfs2: Multi-block allocations in gfs2_page_mkwrite
45 7c5305fbd68a da3c604755b0 [SAME] gfs2: Fix end-of-file handling in gfs2_page_mkwrite
46 162524005151 4525c2f5b46f [SAME] Rafael Aquini's slab instrumentation
47              a06a5b7dea02 [    ] GFS2: Add go_get_holdtime to gl_ops
48              8ba93c796d5c [    ] gfs2: introduce new function remaining_hold_time and use it in dq
49              e8b5ff851bb9 [    ] gfs2: Allow rgrps to have a minimum hold time

Missing from recovery25:
The missing:
Compare script generated at: /tmp/compare_mismatches.sh

6. gitlog.find

Finally, I have gitlog.find, a script to help me identify where the upstream versions of my patches are and each patch's current status. It does this by matching the patch description. It also generates a compare script (again, using Kompare) to compare the current patch to the upstream counterpart:

$ gitlog.find
-----------------------[ recovery25 - 50 patches ]-----------------------
(snip)
11 340d27a33895 Bob Peterson     gfs2: drain the ail2 list after io errors
lo 5bcb9be74b2a Bob Peterson     gfs2: drain the ail2 list after io errors
10 9b3c4e6efb10 Bob Peterson     gfs2: clean up iopen glock mess in gfs2_create_inode
fn 2c47c1be51fb Bob Peterson     gfs2: clean up iopen glock mess in gfs2_create_inode
 9 d2e8c22be39b Bob Peterson     gfs2: Do proper error checking for go_sync family of glops
lo feb7ea639472 Bob Peterson     gfs2: Do proper error checking for go_sync family of glops
 8 9563e31f8bfd Christoph Hellwig gfs2: use page_offset in gfs2_page_mkwrite
ms f3915f83e84c Christoph Hellwig gfs2: use page_offset in gfs2_page_mkwrite
 7 ebac7a38036c Christoph Hellwig gfs2: don't use buffer_heads in gfs2_allocate_page_backing
ms 35af80aef99b Christoph Hellwig gfs2: don't use buffer_heads in gfs2_allocate_page_backing
 6 f703a3c27874 Andreas Gruenbacher gfs2: Improve mmap write vs. punch_hole consistency
fn 39c3a948ecf6 Andreas Gruenbacher gfs2: Improve mmap write vs. punch_hole consistency
 5 a3e86d2ef30e Andreas Gruenbacher gfs2: Multi-block allocations in gfs2_page_mkwrite
fn f53056c43063 Andreas Gruenbacher gfs2: Multi-block allocations in gfs2_page_mkwrite
 4 da3c604755b0 Andreas Gruenbacher gfs2: Fix end-of-file handling in gfs2_page_mkwrite
fn 184b4e60853d Andreas Gruenbacher gfs2: Fix end-of-file handling in gfs2_page_mkwrite
 3 4525c2f5b46f Bob Peterson     Rafael Aquini's slab instrumentation
   Not found upstream
 2 a06a5b7dea02 Bob Peterson     GFS2: Add go_get_holdtime to gl_ops
   Not found upstream
 ^ 8ba93c796d5c Bob Peterson     gfs2: introduce new function remaining_hold_time and use it in dq
   Not found upstream
 H e8b5ff851bb9 Bob Peterson     gfs2: Allow rgrps to have a minimum hold time
   Not found upstream
Compare script generated: /tmp/compare_upstream.sh

The patches are shown on two lines, the first of which is your current patch, followed by the corresponding upstream patch, and a 2-character abbreviation to indicate its upstream status:

  • lo means the patch is in the local upstream Git repo only (i.e., not pushed upstream yet).
  • ms means the patch is in Linus Torvald's master branch.
  • fn means the patch is pushed to my "for-next" development branch, intended for the next upstream merge window.

Some of my scripts make assumptions based on how I normally work with Git. For example, when searching for upstream patches, it uses my well-known Git tree's location. So, you will need to adjust or improve them to suit your conditions. The gitlog.find script is designed to locate GFS2 and DLM patches only, so unless you're a GFS2 developer, you will want to customize it to the components that interest you.

Source code

Here is the source for these scripts.

1. gitlog

#!/bin/bash
branch=$1

if test "x$branch" = x; then
    branch=`git branch -a | grep "*" | cut -d ' ' -f2`
fi

patches=0
tracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`

LIST=`git log --reverse --abbrev-commit --pretty=oneline $tracking..$branch | cut -d ' ' -f1 |paste -s -d ' '`
for i in $LIST; do patches=$(echo $patches + 1 | bc);done

if [[ $branch =~ .*for-next.* ]]
then
    start=HEAD
#    start=origin/for-next
else
    start=origin/master
fi

tracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`

/usr/bin/echo "-----------------------[" $branch "]-----------------------"
patches=$(echo $patches - 1 | bc);
for i in $LIST; do
    if [ $patches -eq 1 ]; then
        cnt=" ^"
    elif [ $patches -eq 0 ]; then
        cnt=" H"
    else
        if [ $patches -lt 10 ]; then
            cnt=" $patches"
        else
            cnt="$patches"
        fi
    fi
    /usr/bin/git show --abbrev-commit -s --pretty=format:"$cnt %h %<|(32)%an %s %n" $i
    patches=$(echo $patches - 1 | bc)
done
#git log --reverse --abbrev-commit --pretty=format:"%h %<|(32)%an %s" $tracking..$branch
#git log --reverse --abbrev-commit --pretty=format:"%h %<|(32)%an %s" ^origin/master ^linux-gfs2/for-next $branch

2. gitlog.id

#!/bin/bash
branch=$1

if test "x$branch" = x; then
    branch=`git branch -a | grep "*" | cut -d ' ' -f2`
fi

tracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`

/usr/bin/echo "-----------------------[" $branch "]-----------------------"
git log --reverse --abbrev-commit --pretty=oneline $tracking..$branch | cut -d ' ' -f1 |paste -s -d ' '

3. gitlog.id2

#!/bin/bash
branch=$1

if test "x$branch" = x; then
    branch=`git branch -a | grep "*" | cut -d ' ' -f2`
fi

tracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`
git log --reverse --abbrev-commit --pretty=oneline $tracking..$branch | cut -d ' ' -f1 |paste -s -d ' '

4. gitlog.grep

#!/bin/bash
param1=$1
param2=$2

if test "x$param2" = x; then
    branch=`git branch -a | grep "*" | cut -d ' ' -f2`
    string=$param1
else
    branch=$param1
    string=$param2
fi

patches=0
tracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`

LIST=`git log --reverse --abbrev-commit --pretty=oneline $tracking..$branch | cut -d ' ' -f1 |paste -s -d ' '`
for i in $LIST; do patches=$(echo $patches + 1 | bc);done
/usr/bin/echo "-----------------------[" $branch "-" $patches "patches ]-----------------------"
patches=$(echo $patches - 1 | bc);
for i in $LIST; do
    if [ $patches -eq 1 ]; then
        cnt=" ^"
    elif [ $patches -eq 0 ]; then
        cnt=" H"
    else
        if [ $patches -lt 10 ]; then
            cnt=" $patches"
        else
            cnt="$patches"
        fi
    fi
    /usr/bin/git show --abbrev-commit -s --pretty=format:"$cnt %h %<|(32)%an %s" $i
    /usr/bin/git show --pretty=email --patch-with-stat $i | grep -n "$string"
    patches=$(echo $patches - 1 | bc)
done

5. gitbranchcmp3

#!/bin/bash
#
# gitbranchcmp3 <old branch> [<new_branch>]
#
oldbranch=$1
newbranch=$2
script=/tmp/compare_mismatches.sh

/usr/bin/rm -f $script
echo "#!/bin/bash" > $script
/usr/bin/chmod 755 $script
echo "# Generated by gitbranchcmp3.sh" >> $script
echo "# Run this script to compare the mismatched patches" >> $script
echo " " >> $script
echo "function compare_them()" >> $script
echo "{"  >> $script
echo "    git show --pretty=email --patch-with-stat \$1 > /tmp/gronk1" >> $script
echo "    git show --pretty=email --patch-with-stat \$2 > /tmp/gronk2" >> $script
echo "    kompare /tmp/gronk1 /tmp/gronk2" >> $script
echo "}" >> $script
echo " " >> $script

if test "x$newbranch" = x; then
    newbranch=`git branch -a | grep "*" | cut -d ' ' -f2`
fi

tracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`

declare -a oldsha1s=(`git log --reverse --abbrev-commit --pretty=oneline $tracking..$oldbranch | cut -d ' ' -f1 |paste -s -d ' '`)
declare -a newsha1s=(`git log --reverse --abbrev-commit --pretty=oneline $tracking..$newbranch | cut -d ' ' -f1 |paste -s -d ' '`)

#echo "old: " $oldsha1s
oldcount=${#oldsha1s[@]}
echo "Branch $oldbranch has $oldcount patches"
oldcount=$(echo $oldcount - 1 | bc)
#for o in `seq 0 ${#oldsha1s[@]}`; do
#    echo -n ${oldsha1s[$o]} " "
#    desc=`git show $i | head -5 | tail -1|cut -b5-`
#done

#echo "new: " $newsha1s
newcount=${#newsha1s[@]}
echo "Branch $newbranch has $newcount patches"
newcount=$(echo $newcount - 1 | bc)
#for o in `seq 0 ${#newsha1s[@]}`; do
#    echo -n ${newsha1s[$o]} " "
#    desc=`git show $i | head -5 | tail -1|cut -b5-`
#done
echo

for new in `seq 0 $newcount`; do
    newsha=${newsha1s[$new]}
    newdesc=`git show $newsha | head -5 | tail -1|cut -b5-`
    oldsha="            "
    same="[    ]"
    for old in `seq 0 $oldcount`; do
        if test "${oldsha1s[$old]}" = "match"; then
            continue;
        fi
        olddesc=`git show ${oldsha1s[$old]} | head -5 | tail -1|cut -b5-`
        if test "$olddesc" = "$newdesc" ; then
            oldsha=${oldsha1s[$old]}
            #echo $oldsha
            git show $oldsha |tail -n +2 |grep -v "index.*\.\." |grep -v "@@" > /tmp/gronk1
            git show $newsha |tail -n +2 |grep -v "index.*\.\." |grep -v "@@"  > /tmp/gronk2
            diff /tmp/gronk1 /tmp/gronk2 &> /dev/null
            if [ $? -eq 0 ] ;then
# No differences
                same="[SAME]"
                oldsha1s[$old]="match"
                break
            fi
            git show $oldsha |sed -n '/diff/,$p' |grep -v "index.*\.\." |grep -v "@@" > /tmp/gronk1
            git show $newsha |sed -n '/diff/,$p' |grep -v "index.*\.\." |grep -v "@@" > /tmp/gronk2
            diff /tmp/gronk1 /tmp/gronk2 &> /dev/null
            if [ $? -eq 0 ] ;then
# Differences in comments only
                same="[same]"
                oldsha1s[$old]="match"
                break
            fi
            oldsha1s[$old]="match"
            echo "compare_them $oldsha $newsha" >> $script
        fi
    done
    echo "$new $oldsha $newsha $same $newdesc"
done

echo
echo "Missing from $newbranch:"
the_missing=""
# Now run through the olds we haven't matched up
for old in `seq 0 $oldcount`; do
    if test ${oldsha1s[$old]} != "match"; then
        olddesc=`git show ${oldsha1s[$old]} | head -5 | tail -1|cut -b5-`
        echo "${oldsha1s[$old]} $olddesc"
        the_missing=`echo "$the_missing ${oldsha1s[$old]}"`
    fi
done

echo "The missing: " $the_missing
echo "Compare script generated at: $script"
#git log --reverse --abbrev-commit --pretty=oneline $tracking..$branch | cut -d ' ' -f1 |paste -s -d ' '

6. gitlog.find

#!/bin/bash
#
# Find the upstream equivalent patch
#
# gitlog.find
#
cwd=$PWD
param1=$1
ubranch=$2
patches=0
script=/tmp/compare_upstream.sh
echo "#!/bin/bash" > $script
/usr/bin/chmod 755 $script
echo "# Generated by gitbranchcmp3.sh" >> $script
echo "# Run this script to compare the mismatched patches" >> $script
echo " " >> $script
echo "function compare_them()" >> $script
echo "{"  >> $script
echo "    cwd=$PWD" >> $script
echo "    git show --pretty=email --patch-with-stat \$2 > /tmp/gronk2" >> $script
echo "    cd ~/linux.git/fs/gfs2" >> $script
echo "    git show --pretty=email --patch-with-stat \$1 > /tmp/gronk1" >> $script
echo "    cd $cwd" >> $script
echo "    kompare /tmp/gronk1 /tmp/gronk2" >> $script
echo "}" >> $script
echo " " >> $script

#echo "Gathering upstream patch info. Please wait."
branch=`git branch -a | grep "*" | cut -d ' ' -f2`
tracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`

cd ~/linux.git
if test "X${ubranch}" = "X"; then
    ubranch=`git branch -a | grep "*" | cut -d ' ' -f2`
fi
utracking=`git rev-parse --abbrev-ref --symbolic-full-name @{u}`
#
# gather a list of gfs2 patches from master just in case we can't find it
#
#git log --abbrev-commit --pretty=format:"   %h %<|(32)%an %s" master |grep -i -e "gfs2" -e "dlm" > /tmp/gronk
git log --reverse --abbrev-commit --pretty=format:"ms %h %<|(32)%an %s" master fs/gfs2/ > /tmp/gronk.gfs2
# ms = in Linus's master
git log --reverse --abbrev-commit --pretty=format:"ms %h %<|(32)%an %s" master fs/dlm/ > /tmp/gronk.dlm

cd $cwd
LIST=`git log --reverse --abbrev-commit --pretty=oneline $tracking..$branch | cut -d ' ' -f1 |paste -s -d ' '`
for i in $LIST; do patches=$(echo $patches + 1 | bc);done
/usr/bin/echo "-----------------------[" $branch "-" $patches "patches ]-----------------------"
patches=$(echo $patches - 1 | bc);
for i in $LIST; do
    if [ $patches -eq 1 ]; then
        cnt=" ^"
    elif [ $patches -eq 0 ]; then
        cnt=" H"
    else
        if [ $patches -lt 10 ]; then
            cnt=" $patches"
        else
            cnt="$patches"
        fi
    fi
    /usr/bin/git show --abbrev-commit -s --pretty=format:"$cnt %h %<|(32)%an %s" $i
    desc=`/usr/bin/git show --abbrev-commit -s --pretty=format:"%s" $i`
    cd ~/linux.git
    cmp=1
    up_eq=`git log --reverse --abbrev-commit --pretty=format:"lo %h %<|(32)%an %s" $utracking..$ubranch | grep "$desc"`
# lo = in local for-next
    if test "X$up_eq" = "X"; then
        up_eq=`git log --reverse --abbrev-commit --pretty=format:"fn %h %<|(32)%an %s" master..$utracking | grep "$desc"`
# fn = in for-next for next merge window
        if test "X$up_eq" = "X"; then
            up_eq=`grep "$desc" /tmp/gronk.gfs2`
            if test "X$up_eq" = "X"; then
                up_eq=`grep "$desc" /tmp/gronk.dlm`
                if test "X$up_eq" = "X"; then
                    up_eq="   Not found upstream"
                    cmp=0
                fi
            fi
        fi
    fi
    echo "$up_eq"
    if [ $cmp -eq 1 ] ; then
        UP_SHA1=`echo $up_eq|cut -d' ' -f2`
        echo "compare_them $UP_SHA1 $i" >> $script
    fi
    cd $cwd
    patches=$(echo $patches - 1 | bc)
done
echo "Compare script generated: $script"

 

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About the author

Bob Peterson - Bob Peterson is a Linux kernel developer working for Red Hat on the GFS2 file system.