android - Shell Script to remove lines of text in a text file -

android - Shell Script to remove lines of text in a text file -

how can remove line of text in file if exists?

so far guessing

#!/sbin/sh mount -o remount,rw /system; # create backup first cp /system/build.prop /system/build.prop.bak; # append if [ grep -o 'wifi.supplicant_scan_interval' <<</system.build.prop > 1 ]; echo "yo"; fi; mount -o remount,ro /system;

however, shows me yo no matter of > 1 or < 1 (it exist in file), part seems wrong, also, don't know how remove line?

can help?

code update #!/sbin/sh mount -o remount,rw /system; function check_prop(){ busybox grep $1 /system/build.prop; homecoming $?; } # create backup first cp /system/build.prop /system/build.prop.bak; echo $(check_prop 'wifi.supplicant_scan_interval'); # append if [ $(check_prop 'wifi.supplicant_scan_interval') > 1 ]; # stuff here? echo 'yo'; fi; mount -o remount,ro /system;

is returning me blank line, , yo. if alter < 1 same thing

sed '/wifi.supplicant_scan_interval/d' inputfile

would remove lines matching wifi.supplicant_scan_interval

eg

$cat input hello world hai $sed '/world/d' input hello hai

if want delete line file utilize -i alternative action inplace

sed -i '/wifi.supplicant_scan_interval/d' inputfile

edit

using grep print lines except lines match patter.

grep -v 'wifi.supplicant_scan_interval' inputfile

eg

$ grep -v 'world' input hello hai

the -v alternative negation.

android bash shell sh